This invention relates to the field of enclosing material in packaging material, such as ill netting, bags, or casing. More particularly, the invention relates to the field of enclosing edible food products, such as hams, poultry, sausages, and cheeses, in packaging material, such as in netting or casing. More particularly, this invention relates to the field of enclosing material such as edible food products in packaging material such as tubular netting and closing the ends of the netting with a clip.
Various materials are commonly packaged in netting, including edible food products. Whole chickens, for example, are commonly sold enclosed in a clear plastic bag, which is sealed by a clip. Sausages are created by extruding a pasty mixture of chopped meats and spices into a tubular casing, which is sealed at either end by a clip. Some items such as fruit and potatoes are packaged in nets in order to sell the items in lots, such as by the dozen or by weight. These types of items are often placed in bag-type nets, the top of the bag is gathered, and a clip is applied to close the bag. A label may also be placed at the neck of the gathered bag to be clipped to the bag, with identifying information such as the provenance, weight, lot number, or expiration date of the items. Often this or other information is contained in a bar code on the label. Please note that these types of items are also packaged in other types of mesh-style bags or in plastic bags, which are still clipped closed as with bags made of netting.
Larger items such as hams, whole poultry, sausages, and cheeses, are packaged in netting for ease of handling and for further processing. For example, hams and turkeys are often encased in tubular netting. One end of the tube is closed with a clip, the item is placed within the netting, the netting is gathered tightly around the item, a clip is applied to enclose the item within the netting, and the netting is severed. Often, a loop is formed in the netting to create a handle on the package, to ease handling of the items, which may be heavy, and to allow consumers to lift the items without actually touching the items. As with bag-type netting, as described above, a label may be attached to one of the clips to provide identifying information.
In some situations, items are packaged in netting in order to enhance the appearance of the items after processing. For example, sausages, hams, and cheeses are often encased in tubular netting, as described above, prior to processing. During processing, such as in a smokehouse, the item expands within the netting and pushes through the mesh of the netting. After processing, the netting is removed and discarded. The item retains a dimpled appearance that is considered pleasing to consumers.
In all situations described above, the bag, the casing, and the netting must be closed and a clip is the commonly-accepted means for closing food packaging material, whether it is a bag, a net, or a casing. Manual and automated clippers are commercially available. An automated clipper for poultry is described in U.S. Pat. No. 6,883,297 to Kirk et al., which is assigned to the assignee of the present application and the disclosure of which is incorporated by reference. An apparatus for clipping sausages is described in U.S. Pat. No. 7,063,610 to Mysker, which is assigned to the assignee of the present application and the disclosure of which is incorporated by reference.
The clips for a clipper generally are supplied on either a reel or in stick form. Clips can be made of metal or plastic. They are formed in an upside-down U shape, similar to a common office staple. A prior-art metal clip is described in, for example, U.S. Pat. No. 6,401,306 to Hanten et al., which is assigned to the assignee of the present application and the disclosure of which is incorporated by reference.
It is important that the clip keep the netting closed. If a consumer picked up a large item such as a turkey and the netting slipped within the clip, an injury could result, either from the turkey falling out one end of the netting or by the handle pulling tightly about the consumer's fingers. During smoking of hams or sausages, if the netting did not hold tight about the item, the item would not expand through the mesh of the net and would not obtain the dimpled appearance that is considered desirable. Prior art methods to prevent slippage of netting through a clip have not been totally satisfactory. Accordingly, there is a long-felt need, especially within the food packaging industry, for a clip that will securely close netting and prevent slippage of the netting through the clip.
An exemplary prior art clip is illustrated in FIG. 1. The clip 20 consists of a top section 22 joining two legs 24, 26 together. Please note that various configurations of clips exist. The clip 20 shown in FIG. 1 is round-shouldered, but square-shouldered and other configurations exist.
A plurality of clips 20A, 20B, 20C, etc., are joined together as illustrated in FIG. 2 to form a stick or cartridge 30. The clips 20 are held together by a variety of ways, such as glue, tape, plastic guides, or other means, none of which are within the purview of the present invention. The cartridge 30 is inserted in a clipper 32 and moves along a rail 34, as shown in FIG. 3. Additionally, a guide rail 36 on top of the cartridge 30 holds the clips 20 to the rail 34. It is important to maintain the clips 20 on the rail 34. The first clip 20A of a cartridge 30, consisting of clips 20A, 20B, 20C, etc., must be precisely located over a die and under a punch in order to securely fasten the neck of the netting. Maintaining registry of the clips 20 on the rail 34 within the clipper 32 is important to precise control of the clipper 32. Maintaining fast movement of the clips 20 along the rail 34 is also important, especially for high-speed automated manufacturing processes. Accordingly, maintaining registry of the clips and keeping the cartridge moving has been a problem for clipper manufacturers.
To package items in packaging material as described above, whether in bag-type nets, casing, or tubular netting, the netting is gathered into a neck that will fit within the space 38 defined by the legs 24, 26 and the inside face 40 of the top section 22. A punch presses down on the top section 22, forcing the legs 24, 26 into a die which folds the legs 24, 26 inwardly, thereby compressing the formerly open space 38 into compressed space 42 and fastening the neck. A compressed clip 20 is shown in FIG. 4, having legs 24, 26 folded inward.
If enough force is applied to the netting, it will pull through the now-compressed space 42, with undesirable results. One prior art solution to prevent this occurrence is to have the legs 24, 26 fold next to each other, as illustrated in, for example, FIGS. 6b and 8b of the '306 patent cited above. Another technique is to apply a cross-hatch surface pattern to the inside face 38, to increase the friction between the clip 20 and the netting. Neither of these techniques has proven completely satisfactory to ensure adequate fastening of the clip 20 about the neck to keep the item tightly bound within the netting. Additionally, the application of cross-hatching requires another step in the manufacturing process, thereby increasing the cost of the clips, and the increased friction created by the cross-hatching causes difficulties in travel of the clips along the rail of a clipper. Accordingly, there has been a failure by others to solve the problem described above and the long-felt need for a solution still exists.
Accordingly, a need exists for an easily-manufactured clip that that will maintain registry on the rail of a clipper and can be moved at high speed along the rail of a clipper. A need also exists for an easily-manufactured clip that will securely fasten a neck of packaging material and prevent the packaging material from being pulled through the clip. The present invention meets these needs.